Automatic telephone system



y 0 R. G. RICHARDSON AUTOMATIC TELEPHONE SYSTEM Original Filed Oct. 1.3, 1917 2 Sheets-Sheet l J FQ jigdzzeg EEAchurflsun.

I 1,627,929 y 10 1927' RICHARDSON AUTOMATI C TELEPHONE SYSTEM Original Filed Oct. 1.3, 1917 2 sheaths-Sheet 2 M E EL'aZ-w ispn. H12 arggy Patented May 10, 1927.

UNITED STATES PATENT orrics.

RODNEY G. RICHARDSON, OF CHICAGO. ILLINOIS, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO AUTOMATIC ELECTRIC INC., OF CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE;

AUTOMATIC TELEPHONE SYSTEM.

Application filed October 13, 1917. Serial No. 196,380.

My invention relates in general to automatic telephone systems, but more particularly to such systems as comprise main and branch exchanges interconnected by trunk 6 lines, the branch exchanges being of the type at present used in large numbers to supply telephone service to large manufacturing es tahl'shmen'ts. department stores, and the like; andthe principal object of the inven- 10 tion is to provide means whereby main to branch exchange calls may be transferred automatically from one station to another at a branch exchange while the main exchange subscriber waits on the line.

Ordinarily if it should be desired to trans fer a call from one stafion to another at the branch the main exchange subscriber would have to hang up his receiver and release the entire trunking connection, after which the connection would be reestablished precisely as before with the sole exception. in accordance with the usual practice. of the two final digits which control the final connector at the branch. ,It is extremely desirable to avoid the necessity 'of thus releasing 'the trunking portion of the connection, for to do so involves great inconvenience and Waste of time on the part of the main exchange subscriber. and may also result in the loss of the trunk line during busy periods; and it will be apparent that a System in which incoming calls at abranch exchange can be transferred without releasing the trunk line in use will be very advantageous in praetice.

lVith this object in view, therefore. I have designed a simple and effective method of transferring calls automatically, under local control, the essential features of which are fully described and explained in the followin specification, and illustrated in the drawings forming a part thereof. 7

'lhe drawings conqirisingvF'i'gs. 1 and 2, should proper y be arranged in order with corresponding lines at the adjacent edges thereof-in a|ign1i1cu.l; and when so positioncil show"diagrammatically a trunk line 2 2 terminatingiu theincoming connector l) (Fig, 1) ate branch exchange, two substations [land A (Fig. 2) which are accessible to the incoming connector, and indiviiliial line or trunlc selecting switches C and (1 which arerasf-iociat etl with the line of substations. A and A, respectively. There is also shown to the right of Fig. 2 a trunk line comprising conductors 130, 131 and 132 which terminates in a local connector switch (not shown).

Fig. 3 shows a modification of the connection of relay 8 of Fig. 2. This modification arranges the circuit so that the first called party is automatically disconnected from the connection afterlhe has transferred the. call to another called party in accord ance with one of the objects of this invention.

The subscribers stations such as the substations A and A are of the usual common battery type in which the transmitter and receiver are connected in series. Each substation is also provided with a calling device which is preferably of the type in which a reciprocating dial is operated by the'sub scribcr to produce series of interruptions in the line circuit in accordance with the digits in called numbers. A calling device which is suitable for the purpose is shown in the British patent to Dicker #29,654of 1910.

The individual line switches, such as the line switches C and C, are of'the well known rotary type in which the wipers have no normal position. A rotary line switch of suitable construction is described in the patent to Lamb, No. 1,193,160, granted August 1st, 1916.

The connector switches including both the incoming connectors and the local connectors are mechanically of the type disclosed in the patent to Faith, Erickson'and Erickson, No. 815,176, granted March 13, 1900. The circuits are modified, however, in ac cordance with the two-wire system of control and the circuits of the incoming connectors are further modified to accomplish the objects of this invention as will be fully. explained hereinafter. In regard were local connectors these switches are preferably of the type commonly known as selector connectors. the construction and utility of which are explained fully in the patent to Dealtin No. 1,164,479, granted December 14, 1915.

The main exchange is assumed to be of the modern two-wire type well known in the art and needs no detailed description. Reference is made, however, toit-he patent to A. H. Blessing, No. 1,176,269, granted March 21, 1916, whiclnshows two-wire se:

tors.

lector, connw-tor and repeater circuits. The trunk line comprising conductors and 3 may be one oil a group of trunk lines which terminate in a certain second or third selector level at the main exchange, and which extend through repeaters to the branch we change, terminating there in. incoming connectors like the connector I) (Fig. 1). As shown herein the trunk line terminating in the incoming connector l) is adapted for use in one direction only. that is. it can only be used on calls from the main exchange to the branch exchange. Connections in the reverse direction may be handled by a separate group of trunk lines (not shown) which are accessible to the local selector connec- It will be understood of course that by the usual expcdients the trunk line shown can be adapted for two'wajv service. llut since my invention is not particularly concerned with this it has been considered advisable to show the trunk' line in the simplest form possible.

Considering the local trunking in the branch exchange somewhat more in detail. the banks of all the individual line switches are connected in multiple and contain terminals of trunk lines extending to the local selector connectors as is usual and also in accordance with this invention contain terminals of special trunks which extend to the incoming connectors. Thus in Fig. there is shown a local connector trunk comprising conductors 130 to 182, inclusive, which is znultipled to the contact set comprising contacts llet 101117 in the bank of the line switch C and also to a contact set comprising contacts 122 to 12%, inclusive,

in the bank of the line switch C". A special trunk extending to the incoming connector D is also shown comprising conductors 85 to 88, inclusive, which terminate in the contact set comprising bank contacts 118 to 121, inclusive, of line switch C, being also multipled to corresponding contact sets in the line switch- C and. the other line switches. Sufiicient local selector connectors will of course be provided to handle the maximum number of simultaneous local and branch to main, exchange calls. Likewise the incoming connectors aml associated trunk lines will also be provided in sufficientnumber to handle the main to branch exchange calls. Ordinarily more local conncctors will he required than incoming connoctors, and if we assume that. there are ten of the former and 5 ol' the latter everytbird contact set in the line switch banks may U0 assigned to a special inpoming connector trunk. This means of co'nrse that the two kinds of trunks which terminate in the line switch banks are not segregated but on the contrary are arranged alternately. It will he observed that the line switches are provided with fourth wipers which in the case contact set comprising bank contacts to 74, inclusive, in the bank of the incoming connector, being multipled in the usual way to corresponding contact sets in the banks of the other incoming connectors. There is also shown a groupof normal conductors comprising conductors 140 to 142, inclusive,

which it will be understood extend to multiple contact sets in the banks of the local conncctors. The line of substation A and the other lines in the branch exchange are similarly connected.

lVhile I have shown throughout the drawings a plurality of batteries it will be understood that there is preferably but one battery having its positive pole grounded. In order not to encumber the drawings unnecessarily, reference characters have not, been applied to the separate batteries shown, and it will be understood that where in'the specification a circuit is traced to battery it extends to the live or ungrounded pole of the main battery at the branch exchange. There isalso provided a small auxiliary battery B shown near the bottom of Fig. 1 whose function will he explained hereinafter. The. roterence characters Q and IR- indicate, respectivcly, a busy signalling machine and iriter-.

mittent ringing equipment which are oftbe usual type common in other automatic telephone systems.

Having given a brief description of the apparatus involved I will now proceed to explain the operation of the invention. For this purpose it will first be assumed that a calling subscriber inthc main exchange dcsires to obtain a connection with the branch exchange subscriber at substation A ,fan'd it will be further assumed that the calling 'subscriberhas operated a series of automatic switches in the main exchange. to establish connection with the trunk line (Comprising conductors 2 and 3 which terminate at. the branch exchange in the. incoming cormect-or I). lVhen connection with the trunk line is established a bridge is closed across the. trunk conductors in the usual manner at the repeater in the main exchange and the line rc lay 4 of the incoming connector is energized in the well understood manner. Upon attracting its armature relay 4 completes the usual circuit for the slow acting release relay .3, whi h upon energizing in turn, prepares the usual circuit for the. vertical and rotary magnets 18 and if). The calling subscribcr may now operate his calling device in :ir-c-iidainc with the iirst of the two \ligis which are to control the operation of the connector l A series of interruptions is ac ord ngiy produced in his line circuit which are repeated in the well knownmanncr by the ma n exchange repeater into the cncrgizing circuit of the line relay 4. The line relay will therefore be deenergized a number of times andat each dcenergization transmits an impulse of current to the vertical magnet over the following path: ground at G, armature 26 and its resting contact, armature 27 and its working COllttll t. winding of the low resistance slow acting private control relay 1t winding of the vertical magnet 18. and the side switch wiper 23 in first position to battery. By the operation of the vertical magnet the shaft of the incoming connector is raised step by stop until the wipers (30 to 61. inclusive, arrive opposite the required .horizontal level, of bank contacts. Relay 16 is energized in series with the vertical magnet, and being slow acting, retains its armature during the series of impulses to clo'e an energizing circuit for the private inagne. 17. At the end of the vertical movement of the switch, relay 16 and the private magnet are dcenergized, the latter controlling the side switch in the usual. manner to advance its Wipers to their second position.

The calling subscri'ier may now operate his calling device in accordance with the final digit, thereby producing another series of interruptions in his line circuit which are re; peated the line relay 4. Now,however, the side switch wiper 23 being in its second position, the line relay sends at each deenergization an impulse to the rotary magnet 19 in the well understood manner. In response to these impulses the rotary magnet is operated to rotae the wipers to 64, inclusive, until they C(illlit into engagement with bank contacts to 74:. inclusive, these contacts being the once comprising the contact set which is allotted to the line of substation A. The slow acting relay l6 and the private magnet- 17 are operated during the second series of impulses as before and at the end of the rotary movement of the switch if the called line is idle the private magnet is deenergized to advance the side switch wipers to their third position.

When the side switch wiper 24 comes into engagement with its third position contact point a circuit is completed for the combined cut oil and switching relay 102 of the individual line switch (3 as follows: ground at (F, auxiliary battery B, resistance 56, side switch wiper 24 in third position. teat wiper (32, test contact '72, conductor 82, windmy, of relay 102, and the winding of the as before to cause deencrgizations ofstepping magnet 10+ to battery. Relay 102 is operated over the above circuit. to cause its armaturi-s to break away from their back contacts thus clearing the line of substation A of its normal battery and ground conneclions in the line switch. Owing to the interlocking arrangement between the armalurcs ot relays 102 and 103, however. relay 10:! is not able to fully attract its armature and the wipers ot' the line switch accordingly remain disconnected. Ground potential (as increased by lhe auxiliary battery B) extends to multiples of test contact 72 in the banks of the other incoming connectors and also by way of conductor 141 to the multiple test contacts in the banks of the local connectors in order to render the line of sulwtation A busy. At the connector D the switching relay 15 is energized in parallel with the relay 102 of the line switch C over a branch circuit which may be traced from the test wiper 62 by way of the winding of the said relay 15 and the side switch wiper 2:3 in third position to battery. Upon energizing the said relay 15 completes a signalling circuit over the called line as follows:

ground at G ringing generator Gen, contact of the ringing interrupter IR, resting contact of armature 41 and the said armalure, armature 55 and its working contact, wiper 64, bank contact 74, conductor 84, line conductor-JUL through the ringer at substation A, line conductor 100, conductor 81, bank contact 71, wiper 61, working contact of armature 54 and the said armature, armature 37 and its resting contact, upper winding of the ring cut oil' relay 10, and the main battery to ground at G. By the operation of the ringing, equipment IR the ringing generator (ten is interu'iittcntly cut out of the above circuit and the ground connection at (i is substituted therefor from which it follows that the ringer at substation A will be sounded at intervals to call the subscriber to the telephone. The ring cut off relay 10 is so adjusted that it does not energize as long the receiver at the called. station remains on the hook.

The required connection has now been completed and the bell at the called station is being operated intermittently. When the receiver is removed the cut off relay 10 at the connector I) is instantly energized either by current from the main battery alone or by current from the battery and ringing generator in series, and upon attracting its armature establishes a locking circuit for itself as follows: ground at G, otl' normal contact 21 (closed at the first upward movement ot the switch shaft), armature 38 and its working contact, and the lower winding of the cut oil relay 10 to battery. The ring cut oil relay 10 also opens a contact in the busy signalling circuit at its armature 40, prepares a circuit for the relay 1]. at its armature 39, and at armatures 37 and 41 disconnects its own upper winding and the lead from the ringing machine and closes the talking circuit. The back bridge relay 9 is now connected in bridge of the called line and is energized in the usual way over the called line circuit. At this point it should be mentioned that the ring out 01f relay 10 is so adjusted that armatures 37 and 41 engaged their working contacts before the armature 39 engages its working contact. This adjustment is made in order to connect the back bridge relay 9 across the called line and permit it to energize before the contact in the circuit of relay 11 is closed at armature 39. Relay 11 is given a stiff adjustment and may be permitted to receive a slight impulse of current during the energization of relays 10 and 9 without ill effect, it being understood that it remains inoperative at this time. In addition to opening the circuit of relay 11 at its armature 36 as.

explained, the back bridge relay 9 prepares at its armature 35 a circuit for relay 12 which will be described later.

The required connection has now been established. Talking current for the transmitter at the calling station may be supplied .in any suitable manner at the main exchange, preferably through the windings of the line relay of the repeater; while talking current for the transmitter at the called substation A is supplied through the windings of the back bridge relay 9. The voice currents follow the path shown in heavy lines which will be apparent without further explanation.

So far there has been nothing unusual in the process of setting up the connection. The release of the connector D is under the control of the calling subscriber who by replacing his receiver will deenergize the relays 4 and 5 and thus close the circuit of the release magnet 20, 011 normal contact 22 now being closed and relay 7 being deenergized. We will suppose,'however, that before finishing with the business he has in hand the. calling subscriber finds it necessary to communicate with some other person or oflicial of the concern served by the branch exchange. The necessity for calling a second party may arise from various reasons with which we are not especially concerned, perhaps the right party was not obtained in the first place: but however this may be, occas'ons on which calls must be transferred will arise quite frequently. Assuming then that connection with another party is de sired, the subscriber at substation A for instance, the party at substation A will offer to transfer the call and this being agreeable to the calling subscriber will proceed to do so in the following manner.

The first operation is to pull down the receiver hook at substation A for an instant and then release it. When the receiver hook is ulled down the circuit of the called line is roken and the back bridge relay 9 is deenergized to complete a circuit for relay 11 as follows: ground at G", resting contack of armature 36 and the said armature, working contact of armature 3S) and the said armature, contact springs contrrilled by armature 44 of relay 11, the winding of the said relay, contact springs controlled by the armature of relay 16, and the winding of the private magnet 17 to battery. Relay 11 is suilicientl high in resistance to prevent the operation of the private magnet. Upon energizing, relay 11 closes a locking circuit for itself at its armature 44 in an obvious manner and at its armature 43 prepares a circuit for the upper winding of relay 12. The operation of armatures 42 and 45 of relay 11 is without particular function at this time. The receiver hook at substation A is held down momentarily and as soon as it rises the back bridge relay 9 is again energized. A circuit for relay 12 is now completed as follows: ground at G, armature and resting contact of the common relay 25, common conductor 57, armature 35 and its working contact, working contact of armature 43 and the said armature, and the upper winding of relay 12 to battery. Upon energizing, relay 12 closes a locking circuit through its lower winding by way of its armature 47; at the resting contact of armature 46 disconnects ground G" from conductor 87 and from test contact 120 and its multiples in the banks of the individual line switches; at the working contact of the same'armature completes an energizing circuit through the relay 13 in series with the common relay 25; and at its armature 48 closes a circuit for the stepping magnet 104 of the line switch C as follows: grounded test contact engaged by the test wiper 112 (test contact 116 or similar test contact associated with some other trunk), test wiper 112, conductor 83, bank contact 73, wiper 63, armature 48 and its working contact, armature 51 and its resting contact, winding of the low resistance slow acting relay 14, wiper 60, bank contact 70, conductor 80, interru ter contact of the stepping magnet 104, an the winding of said stepping magnet to battery. Be fore proceeding it will be necessary to know certain relay adjustments that are necessary to insure correct operation. Armature 48 of relay 12 is adjusted to close the circuit including relay 14, the circuit just traced, before armature 46 closes the circuit of relay 13, thereby permitting relay 14 to energize slightly before relay 13. The attainment of this result may also be facilitatedby relay 13 a stitl' adjustment so that it will not operatively energize until its core is nearly saturated. Relay 13need be only slightly 'relay 14 of the incoming connector.

behind relay-14 in operating, but some differeiice is necessary in ordertto permit relay .14 to .close its own CllCLllt'jltZ its armature before it is opened at the armature 51 of relay 13,. it is aiso necessary to have armaseparate. from its restmgcontact and its multiples in the-banksiof the other.

line switches grounded after ground G is disconnected by the operation of armature a!) of relay 13.

An energizing circuit has now been completed for the stepping magnet 104 of the line switch 0-, which includes the test wiper 112 of the line switchand the slow acting Since the stepping magnet 10st interrupts its own circuit, "it will operate intermittently and the line s\-vit,ch= will be advanced, similar to a finder 'sfivitch, in search of the special trunk line extending back to the i-ncoming connector I). The hunting movement of the line switch C is under the control of the test wiper 112 and will continue as long as this test wiper engages grounded test contacts such as the test contact 116. Inasmuchas all test contacts engaged by the wiper-- 112 which are associated with local trunk lines 'are permanently grounded, and inasmuch grounded, the advance of the line switch C- will continue until the test wiper 112 arrives at the test contact 120 fr'oni which ground potential has been removed by'the operation otrelay 12 of the incoming connector. It

should be noted at this point that the cut ofi relay 102 of the line switch, this held energized while the line switchis operating as a finder switch by current flow from .theauxiliary battery 13. arrives at test contact 120 then since it finds no ground potential the circuit [of the relay 14' at the connector and the stepping magnet Hit of the line switch will be broken and the line switch (J will come to rest with; itswipers 110 to 1123, inclusive, in engagement with bank contacts 118 to 121, inclusive,

Hlow acting relay [4 which during the operation of the line switch (I l iasmaintalncd its armaturcs continuously attracted is nOw'deenergized and at the working contact of armature of relay 13 en'gages its An energizing circuit is thus completed for W'hen the test wiper 112.

release magnet 20, and the oiffnormal contact 22 to battery. Y

By the operation of the release magnet/ 20 the incoming connector D is restored to normal position in the usual manner. Atthe beginning of the release of the switch the energizing circuit of the cut off relay 102 of line switch 0 is .openedat the side switch wiper 2a of the connector (or attest wiper 62, it is immaterial which), and this relay immediately deenergizes. The receiver be ing off at substation A the line relay 103 is now energized in the usualmanner over the line circuit and upon attracting its armature closes a new'energizingcircuit for the relay 102 asfollows': ground at G", armature 109 and its working contact,'windin of the relay 102, interrupter contact of tie stepping magnet 104', and the winding of the stepping magnet to battery. At the same time that the above circuit is closed the line relay also connects the test wiper 113 to the junction of relay 102 and the stepping magnet as follows: test wiper 113, armature 107 and its resting contact, armature 108 and its work.- ing contact to the said junctionpoint. There being no ground potential upon the test c0ntact 121, it having been removed by the deenergization of the relay 1 10f the mcomin connector, the stepping magnet 104 'willcnrit be operatedand the relay '102-will instantly energize to extend the line conductoi's and 101 by way of its armatures 105 and 106 to the line wipers 1101and 111, respectively,

the relay 8 of the incoming connectorv as follows: ground at G, lower winding of .relay 8, conductor 85', bank contact 119, wiper 111,

working contact of armature 106 and the said armature, line conductor 10; 1',"t 0 and. through the'subst'ati'on A, linecondu'ctor v 100,

armature 105 and its working contact/swipe!- 110, bank contact-11s, conductor 86, and the I upper windingo f relay 8 .to' battery-.- Upon energizing, relay 8 completes a circuitfor the slow acting relay "7. at its armature The relay operations at line switch 0 "by which the line of substation A is connected to the special trunk are initiated atthe beginning of the release of the incoming connector-and since they take place very rapidly the relay 8 of theconnector will be energized some time before the connector hasbcenentirely restored to normal position When relay 7 cnergizcs'therefore in response to the closure of its circuit by the line relay a holding circuit will be completed for the re My 102 of the line switch C as follows:

ground at ti working contactsof armature iii), armature 4!) and its working contact,

conductor 58. hank contact 121, test wiper 1 l3, armature 107 and its working contact, winding of relay 102, and the winding of the stepping magnet 104 to battery. As soon as llO the connector D becomes completely restored the oil normal contacts are broken andat otl normal contact 21 the locking circuits oi relays 1U, 11 and 12 are opened. These re-. lays accordingly deenergize and relay 12 breaks the 'circuit including the relay 13 and the common relay 25. .W hen the relay 131loenergizes the holding circuit for the relay 102 of the line switch 0 is altered slightly without being opened, however,'the springs controlled by the armature 49 being of the make before break type. By the deenergization of the common relay 25 the common conductor 5.7 is again connected to ground G and calls may now be transferred at other connectors in the group. .It will be understood of course that the function of the relay 25 is to prevent two line switches from being operated as finder switches simultaneously. Y

The foregoing-operation by which the line of substation A has been extended 'into connection with the special trunkdea'dmg back to the incoming. connector andjflwherby the said connector hasbeen rclea's'ed haveoccurred automatically in response to the momentary pulling down of the receiver hook at the substation. These operations take place with great rapidity aiid are completed within not more than one seconds time. The subscriber at substation A may now proceed to call the number of substation A. At the first operation of the dial a series of interruptions is produced ,in the circuit of the relay 8 of the incoming connector, thereby causing this relay to deenergize'n'iomentarily a corresponding number of times. At each 'dcenergization ofthis linerelar a circuit is completed for the vertical magnet 18 as follows: ground at'G,- resting contact of armature ilti and the said armature, armature 34 and its resting contact, working contact of armature 31 and the said armature, winding of theyertical magnet 18 and the side switch wiper 23 in first position l0 battery. -.lhe above circuit of; the verticalmagnet is. substantially the same as the one previously described except that it is controlled by therelays 8 and 7 of the 'eonnec' tor rather than by the relays 4 and 5. Evidently then, the connector switch D is operated in response to these series of impulses and a subsequent series of impulses to establish connection with the line of substation A. The operation of the conncctt'n' under these circumstances being precisely like its operation in the first instance it will be unnecessary to again explain it in detail. I It should be mentioned. howevcr, that while the connector is o )era'ting under control of the substation A tlie slow acting relay 6 will beenergized in parallel with the operating magne to openlthe incoming line conductors at its armatures 28 and 29. This is done in order that the main exchange subscriber 66 who is waiting on the line may not be disis precisely the same as though substation A were tbc.station lirst called. -lhe subscriber at substation A is still in on the connection, however, in fact all three subscribers are now connected together in what may be termed a three party talking circuit. If

necessary for the proper transaction of the matter under consideration the subscriber at substation A may remain connected; ordinarily, however, as soon as he perceives that the conversation has started satisfactorily on the main connection he will replace his recciver in order to disconnect his own line from the talking' circuit. When the rcceiver is replaced at substation A the energizing circuit of the rela 8 is broken and this relay deenergizes wit tout, however, af- {acting rela (3 in any way for ground G is disconnecttl at armature 36 of the back bridge relay 9. But at armature 33 of the relay 8 the circuit of the slow acting relay 7 is broken and this relay upon ,dcenergizing momentarily interrupts the holding circuit of the. relaylOQ'ot the line switcn C. The holding. circuit is only broken momentarily while the armature SOe f reh'i'y 7 is passing from its working to it s'resting contact but this break is su'llicie'rit topermit 're-' lay 101-3 .to-decnergize at leastpartially,

whereupon it breaks its own circuit at its armature 107. By the deene'rgization of re lay 102 the line switch C rs restored to normal position ready for another-call. In-

case tier-tether should again be removed at'substation A thenline switch C will not again establish connection with "the special trunk line for the test contact 12! isnow connected to ground G" at the resting contact ol' arnmiure :illot' the infcoming connector; the line switch will therefore operate in the usual manner to selcct'a trunk line leadin to an idle local connector switch.

if 'it should be necessary to transfer the call to still another substation. this can be done by the subscriber at substation A in the same way that it was accomplished by the subscriber 'at substation Ans already de-' scribed. Otherwise when the conrersz'iii-zin is finished both subscribeis will l('})lll\7t' il1tll' receiversand the incoming connector i will be released in the usual manner upon the lit-- cnergizations of the relays 4 and it will be noted that while. a call is being.transferred as by the substation A in the case ju t v:-: plainedfor example, the release magnet circult is opened atithe armature 32 of the slow any interference with the branch subscriber (the is transferring the call to another sta- (ion. e

ln the operation of transferring calls as above explained the branchexchange subscribenlirst called and who transfers the conn ectionto another station is permitted to reinain in on the connection 'as long as he de sires; Ordinarily this is the 'preferred method of operating; but it may happen in some installatit'ihsttiatit is" considered best not to have more than tyosubscribers connccted together" simultaneously. other word's, it may; beide'si'red to prevent asub 's criber' whgj-has'transferred 'a call to another subserrbef'friom listening to the subsequent- """ly ensuingflconversation'. In order; to 1 accomplish".'this,' direct ground is removed from the ar'inature 33 of the relay 8 and-' the said armature is connected with arniature 34 as shown. in Fig. '3, both arniatures being supplied with'gro'und by Way of the armature 36 of the backbridge' relay 9'. The-incoming connectors fa' eauis tr nsferred from one station to aningwired in this manner',-when other at. thebranch,gupon-the response of fthe partyQto-"Wlmm the call istranslferred and {t 10 consequent eriergi'aation of the back g'crelay of the connector, relay-9 of the connector ii) for example}; ground -will be .d connected fromithe relay 7- "tonne torwhicheontrolstlie o y 1e, {line switch assoeiated-i vith? the line (if ute'eiive ation 'An alternative method-oftransferring the call which may be mentioned consists" in the operation, of the incomingconnector. by the mainexchange subscriber rather than by? the subscriber at tlie branch exchange ()rdinarily of course it will be most convenient for thebranchexchange subscriberto transfer lie-call, as he is'gencrally more familiar with the local numbers at the brano'hexchaflge than the main exchangesubscriber would be; But at times the called tsjdiscriber ii't the'brauch e xchfange maybe too busy to bother with *the connection and such cases llQjVlll "merely operate his rece ver hook to bring aboutthe release of the incoming con-' hector and will then advise the main; ex-

rhairge subs'criber ot the proper number to call. Ile tvil'li then re lacehis receiver and lthejinain exchange su scriber can complete the connection as previously described.

:switch a circuit is completed for the test retore replace his=rece vtcntialwill berpre ent u mpthe. c test con'tactsy such as 67, which ing busy and a brief explanation will nowhe given of the operationof the incoming'connector I) under such con'ditionslit in the connection first described the substation A had been busy there would have been a, ground potential upon the test. contact 72. lhis being the case-when the connector 1). is operated to establish connection with the line and the Slow acting relay l6 deenergizes at the end of the rotary .inovenientct'ftlre lay 11 as follows: ground on test contact' 72 (either direct or by" way offauxiliary battery Bas explainedl-test wiper-o z side. switch wiper 24 in second posi'ti on,, .resting Contact: oil-armature 39 and; thesaid r i ture, contactsprings.controlled by armatu H oforelay'11,-;windingoi thefsaicl rel: contact springs, controhedty the farmaure; by relay l6, and the vindingof theprivate magnet 17 to battery." Theabove ci'rcuitis completed 'at relay 10 j ust before theusual energizing circuit of the privateigrnagnet sis; broken and serves toniaintain tlie-prhvate magnet energized to hold thefside switch AilptblS in their second position, Upon energizing, relay .l1- locks itself atLitsnrmatore 44 to ground G,:at its arltiature opens the rotary magnet-circuit,- and-yatfits armatore-.45 connects a lead' from the busy signal ling machine Q to 'onesidefof the calling to the-calling subscriberiwhoI will .;b .a v

vised i-xthereby that thewdesired connect is h for the. present one tai nableb He v-il-l' there' 'ver-and gtlie'sa" switches used in, the conneetion-- w i to normal position;

temptsto transfer 11,-; call {thereto te'red by theircon nectoi; test": a operation offthe connector, to zipply no tone in this case: isthe samegas ,just de scribed, exceptrthat the ton ducted to bothfthe calling subset-it r r the called subscriber at A. Upon hearing this busy tone the; subscriber-git A r eplaccs his! receiver thereby breaking circuit previously described .;fox;.-r e l'ay 8, which restores and at armature opens .thevircuit for relay 7. iRelay 7,=u'pon restt-n i'ug, closes the circuitto the release-magimt' 2t) airnur: r10 lure 32, thereby causingv th' c "eiease n'i'agnct to operate and release the vitch iulhe well known manue.r.- lie :ilsofo'pens the circuitof relay 6 fwhic s a slow to re: lease relay and whichremainsui' 'ope-ariut-il. position-long enough to pcigrnitnurgnel"i to release the switch. The :calliug st ll-somber then again remm'cs his iutfcircri opt-rating his line switch C. to again rnuurct him to the special trunks 85 and 86 in themenner he tries the connection again, or he may transfer the call to another local station.-

It will be seen that I have devised a simpie and practical method of transferring calls at a branch exchange without making nector switch controlled by i it necessary for the callingsubscriber at the main exchange torelease the trunkim connection, the ti:an'st'erbeing accomplishe by the subscriber first called at the branch who is enabled by my invention to operate his line switch as finer switcirto" locate the incoming connector in use and release it, whereupon the said connector is again operated. to establish connection with another station. lVhile I have described the invention in its preferred form it will be understood that modifications may be made by persons skilled in the art and I do not therefore wish to limit myself, to the exact form shown and illustrated in,the drmvings but wish to include and have. protectedby Letters Patent all forms and modifications thereof which come within the scope of the appended claims.

What I claim as my invention is:

1. In a telephone system, calling and called shbseribers lines, an automatic conthe calling sub scriber to connect said nes, and means controlled by the called subscriber for releasing and reo crating said connector to connect the said calling line with another called line.

i 2. In a telephone system,"a calling. subscribers line, an automatic connector switch controlled over said line to extend a connection to wit called line, and means controlled over the said called line for releasing and reoperating said switch to transfer the call to another called line.

3. In a telephone system, subscribers lines, an automatic switch operable to extend a connection to any one of said lines as a called line, and means under control of the subscriber on the connected called line for releasingand rcoperating said switch' to transfer the call to another called line.

4. in a telephone system. a trnn kline for,

handling incoming calls to a branchexchange, a connector switch inwvhi'ch said trunk terminates, subscribers line's act-usabble to said switch as called lines, and-means controlled by the subscriber on a connected called line for disconnecting the said -connector from his -line and operating it to transfer the call to another line;

In a telephone system, a trunk line for lnindling incoming calls to a, branch exchange, aconncctor switch in which said trunk terminates and means for operating it to complete connections, and means. controlled at the branch exchange independent at this option.

of the calling subscriber for disconnecting said connector'from any called line to which a connection has'been completed and for reoperating the said connector to transfer the connection to another line. Y i

6. In a telephone system, a subscrilwrs line, a connector switch and means for operating it to connect with said line, means controlied by the subscriber on the connected line for connecting his line with mid con- -nector over a different path, means. for thereafter releasing said connector, and'means controlled by said subscriber for then operating said connector to connect with another .-7. In a .tele hone s stem, a connector switch, a calle subscri i rs line, a calling subscribers line" and means for. controlling s'aid switch over the calling lineto-rpnnect the two lines, means controlled by the'called subscriber-for connecting'his line with said switch over a different path, means for thereafter releasing said connector, and means controlled by the said called subscriber for operating said switch to connect the calling line with a second called line.

8. In a telephone system, subscribers lines, line switches individual thereto for extending said lines when calling, a connector switch and means for operating it to extend aponnectionto one of said lines as avcalled line, means controlled byfthe 'subscriberon the eonn'etietlv called line: for causing his line switch to connect his line with said connector over a difl'erent path, and means for thereafter releasing said connector Inafiteiephonelgsystmy 'gcalling subjscribers li'n'e,'an automatic connector switch controlledover'said lineto extend a connection ,to '0. called line, means controlled over the said called line for-releasing and reopcrating said switch to transfer the call to another calledline, and means .whereby the subscriber whoi'has transferred the call can stayin on the c'oiinection or cut himself out lUpIn a telephone system, subscribers lines, an automatic switch operable to extend a: connection to any one of said lines'as a called line, means under control of the subscriber on theconnected called line for'i'eleasing and reoperating said switch to transfer the call to another called line, and means whereby the subscriber whohas transferred thecall can stay in on the connection or cut himself out at his option.

11. In a telephone system, a trunk line for handling incoming calls to a branch ex-" change, a connector switch in which said trunk terminates, subscribers liueslaccessible from his line and operate -it to transfer the call to another line,;and means whereby the subscriber who has transferred the call can stay in on the connection or cut himself out at his option.

12. In a telephone system, a subscribers line, a" connector switch and means for operating it to connect with said line, means controlled by the subscriber on the connected line for connecting his line with said connector over a different path, means for tliereafter releasing said connector, means controlled by said subscriber for then operating said connector to connect with another line. and means responsive to the replacement of the receiver on the line first called for disconnecting such line from said connector.

13. In a telephone system, a calling subscribers line,.an automatic connector switch controlled over said line to extend a connec tion to a cal'led line, means controlled over the said-called line for releasing and reoperating said switch to transfer the call to another called line, and means for preventing the calling subscriber from releasing said switch while the call is being transferred.

14. In a telephone system, a calling subscribers line, an automatic connector switch controlled over said line to extend a connection to a called line, means controlled over the said calied line for releasing and reop crating said switch to transfer the call to another called line, and means for preventing disturbance in the receiver at the calling station while the call is being transferred.

1.5. In a telephone system, a trunk line for handling incoming calls to a branch exchange, a connector switch in which said trunk terminates, subscribers lines accessible to said switch as called lines, means whereby the subscriber on a connected called line can disconnect the said connector from his line and operate it to transfer the call to another line, and means for.disconnecting the talking conductors of said trunk line from the talking conductors of said switch while the call is being transferred. 1

16. In a telephone system, a trunk line for handling incoming calls to a branch exchange, a connector switch in which said trunk terminates and means for operating it to complete connections, means controlled at the branch exchange independent of the calling subscriber er disconnecting said con- HCCiOl' from any called line towhich a connection has been completed and for reoperating the said connector to transfer the connection to another line, and means for preventing disturbance .inilzthe receiver at the calling station while *thecall is being transferred.

17. In a telephone system comprising main and branch exchanges, a connector at the l anch exchange for completing a main to branch exchange connection, automatic means for releasing said connector when any "station is called without disturbing the rest of the connection, and means whereby the said connector may be reoperated from either the calling or the called station to transfer the call to another station.

18. In a telephone system comprising main and branch exchanges and an interconnecting trunk line, a connector switch at the end of the trunk line for completing main to branch exchange connections, a circuit for opeiating said connector including the two sides of said trunk line in series, and a circuit for releasing said connector from any called station and for holding the trunking connection in order to permit a subsequent operation of the same to transfer the call to another station.

19. In a telephone system, an automatic switch and means for starting it from two different points, two gioups of trunks accessible to said switch, and electromagnetic means for operating said switch when started from one point to select the first idle trunk in one of said groups, and for operating said switch to pass over idle trunks and select a designated trunk in the other group when started from=the other point. 7

20. In a telephone system, a line terminating iii an automatic switch, two groups of trunk lines accessible to said switch, means for operating said switch as a trunk selector to connect sai line with the first idle'trunk in one of said groups, means for operating said switch as a finder switch to connect said line with a designated trunk in the other group, and suitable test circuits in said switch for controlling its operation in each case. 1

21. In a telephone system, a subscribers line circuit, a combined trunk selector andfinder switch at the exchange individual to said line, two kinds of trunk lines teriiiinating in fixed contacts in said switch, and means for opeiatin said. switch as a trunk selector or as a finder switch depending on the kind of trunk line withwhich it is de.- sired to connect.

22. In a telephone system, a subscribers line, trunk lines, -a. line switch controlled over the line when calling to select and connect with an idletrunk line, other trunk lines normally unselectable, means connccting with said subscribers line 'as 0. called line, means for then operating said switch to pick out a desired onel'ot said other trunks and render the same selectable,

and means for then operating said switch as in the first instance when the line is callin whereby connection with said trunk is esta lislied.

23. In a telephone system, a subseribers line and line switch individual thereto, two gioups of trunk lines accessible to said switch, means for causing said switch to function as a trunk selector in response to the init ation of a call over said line to select and connect with an idle trunk line in the first group, means for causing said switch to function as a finder switch when the line is called to select a trunk line of the other group, and means for then causing the switch to function as a trunk selector to establish connection with the trunk thus selected.

24. In a telephone system, subscribers lines and individual line switches, a group of connectors accessible to said line switches when the associated lines are calling and having access to said lines, a second group of connectors also having access to said lines, but inaccessible thereto when the lines are calling, and trunk lines extending to the connectors of said second group, respectively, and terminating in the banks of said line switches.

25. In a telephone system, subscribers lines and individual line. switches, a group of connectors accessible to said line switches when the associated lines are calling and having access to said lines, a second group of connectors also having access to said lines, and trunk lines extending to the connectors of said second group, respectively, and terminating in the banks of said line switches, said trunk lines being unselectable when'the said subscribers? lines are calling,

and means whereby when a line is called by.

a connector of the second group the trunk line associated with such connector may be made selectable.

26. In a telephone system, a connector switch having a line or controlling'relay, a trunk line terminating in said relay, a plurality of subscribers lines accessible to said switch, individual switches for said lines, and a second trunk line multipled in said individual switches andtcrminating in a second controlling relay in said connector.

27. In a telephone system, a connector switch having a line or controlling rolay, a

trunk line terminating in said relay, a plurality of subscribers lines accessible to said switch, individual switches for said lines, a second trunk iine multipled in said individual switches and terminating in a-sc ond controlling relay in said connector, and inductive connections joining the talking conductors of one. trunk line,'rcspectivcly, with the talking conductors of the other.

28. In a. telephone system, a line and an automatic switch vfor connecting said line with other lines, a motor magnet for said switch and a local energizing circuit theretor, a plurality of other sw tches having ac-.

cess to said line, and meansfm closing another energizing circuit for said magnet extending through any one of said other switches.

29. In a telephone system, two electio magnets having high and low resistance windings, respectively, connected in series, tw batteries or other sources of current also conuected in series, there being a closed series circuit through the saidbatteries and magnets and one of said magnets bein inoperative due to the high resistance 0? the other. and means for connecting the junction'of said batteries to the junction of said magnets to operate the normally inoperative magnet. 5

30. In a telephone system, a series of selertor switches, a final connector accessible to the last of said selectors, means for operating-said switches over the two sides of a calling line in series to set jnp a telephone connection, means for releasing said connector while retaining all of said selectors in operated position and while retaining a connection with the called line, and means for reoperating said connector over the calling line to set up a new connection. ii

31. In a telephone. system, a series of selector switches, a final connector accessible to the last of said selectors, means for releasing said switches over the two sides of a calling line in series to set up a telephone connection, means for establishing a substitute for said connection foroperating said connector while retaining vall otsaid selectors in operated position, said releasing means controlled by the subscriber onthe line called, and means for reoperating said connector over the calling. line to set up a new connection.- V Y 32. In a telephone syste'nya series of .selector switches, a final connectoraccessible to the'last of said selectors, meansfor operating said switches over thetwo sides of'a 'calling line in SQIiQS'gtOjSGt up a telephone connection, means for releasing said c'onnector and meansi'v'hcrrby, either party to said connection can reoper'ate said connector to set up a new-connection, while retaining all of said selectors inoperated position.

33. In a telephone system, calling and called lines, automatic switches controlled from one of said calling lines for extendim a connection to one. of saidcalled line-s, anv

means controlled from the said called line tion to it called one of said telephone lines,-

aud means underthe control of the subscribe! on the said called lino for-releasing and reoperating part of said series of auto matic switches without relinquishing the control thereof. 3

35. In a telephone system, telephone lines, automaticswitches, means under the control of a subscriber on a calling one of said 3 lines for operating a series of said automatic switches in order to extend a connection to a called one of said telephone 3 lines, and means, under the control of the subscriber on the said called line for releasing part of said series of automatic switches while still maintaining a connection with the said calling line. i in 36. In a telephone system, telephone lines,

automatic switches, means under the control of a calling -'one'o"f said lines for operat-ing a series of said switches to extend a connection'to a called .one of said lines, is means under the control of the subscriber ou the said called line for releasing part of said series of switches and for extendin}; a connection around the released part of" said series of switches. i 10, 37. In a telepho'ne'syst em, telephone l nes,

automatic switches, means under the control of a calling one of said lines for operating a series of said switches to extend a connection to a calledone of said lines, means including an automatic switch under the control of the subscriber on the said called line for releasing part of said series of switches and for'extending a connection around the released part of said series of :1!) switches. f

38. 'In a telephone system, telephone lines,

automatic switches, means under the con trol of a calling one ofsa'id lines for operating a series ofsaid switches to extend a connection to'a'ca'lled'one of said lines, means including a finder switch under the control of the subscriber on the said called.

line for releasing part of said "seriescf switches and for, extending a connection around the released part ot said series of switches.

, i no. In a telephone systeimteleplioiie lines,

automatic switches, means under thecon- (ml of a calling one of said lines for operi ailing a series of said switches to extend a,

roiilicctlonto a called one of said lines, a line switch individual to" said called line, and means controlled by the subscriber on the called line for causing the operation of ..i. said individual switch to release purl of -\nid series of automatic switches.

l In a telephone system, telephone lines, automatic switches, means under the con -t.rol of ajcalling one of said lines for operailing a series of said switches to extend a connection to a called one of said lines, a line switch individual to said called linc, uj idineans controlled by the subscriber on the-called line for causing the operation of no said individual switch to release part of said series of automatic sw tches, while still maintaining a connection with said calling l-ine.

5 AL In a-telephone system, telephone lines, 66 auto'inatic switches, means under the control of a Subscriber on a calling one of said lim-- for operating a series of said automzui switches to extend a connection to a lilllt'il one of said lines, and means controlled by the subscriber on the called line tori-stublishing a new connection with the calling line before the first established connection is released.

42. In a telephone system, telephone linc:-:. automatic switches, means under the control of a subscriber on a calling one of said lines for operating a series of said automatic switches to extend a connection to ii callcll one of said lines, tlllll-lllt'illls controlled by the subscriber on the called line form-stubone of said lines, and an automatic switch controlled b the subscriber on the t'illluil line for csta dishing :i new connection with the calling line.

44. in a telephone system, telephone lines, automatic switches, means under the control of a subscriber on a callingone of said lines for operating a series of said automatic switches to extend a connection to a called one o'f said lines, and an automatic switch controlled by the subscriber on the called line for establishing i new connection'with the calling line and for releasing part of' said series of switches.

45. In ii telephone system, telephone lines, automatic switches, means under the control of a subfcriber on a cullingone of-said lines for operating a Series of said automatic, switches to extend a connection to n cnlled one of said lines, and an automatic switch controlled by the subscriber on lhe called line for cstiiblishiug'a new connection with the calling line and for releasing part of said series of switches, the subscriber on said called line having means for then-extending n connection to another called one of said lines. 1

46. In a telephone system, calling and called linoautomatic mvitchestzontrollcd from one of said calling lines for establishing a connection with one (ft-said called lines, means controlled by the subscriber on said called line for breaking said connection by releasing one of said automatic switches, and means for reestablishing a' connection with the said calling line before the subcalled lines, means controlled from .one off said calling, llIl63 for establishing a connection with one of said called lines, ineans controlled froin tae called line for establishing Ill) another connection with the calling line thereby releasing thefirst'estahlished con nection, and means for then extending the connection to include a second called line.

48. In a telephone system, calling and called lines, means controlled from one of said calling lines for establishing a connection with one of said call l lines, means controlled from the called line for establishing another connection with the calling line, means then operative to release the first established connection, and means controlled by'tlie subscriber on said calling line for then extending the connection to include a second called line.

In a telephone system, telephone lines, automatic switches, means controlled from a calling one of'said lines for extending the connection to acalled one of said lines, by

way of a series of said switches, means controlled from the called line forreleasing one of said automatic switches while maintaining a connection from the called line thereto, and means controlled from the called line for reoperating the said switch to extend a connection to a second called line after the calling subscriber hangs up.

50. In a telephone system, telephone lines, automatic switches controlled from a calling one of said lines for extending a connection to it called one of said lines, means con-- second called trolled from the called line for releasing one of said automatic switches and for then reoperating it to extend the connection to a one of said lines, and means for releasing the first called line from the extended connection.-

51. Inc telephone system, telephone lines, automatic switches, means controlled from a calling one of said lines for operating series of said automatic switches to extend a connection to- 21 called one of said lines, means controlled from the called line for re leasing and reoperating part of said series of automatic switches to extend the connection to a second called one of said lines, and means for releasing the first called line from the extended connection.

52. In a telephone system, telephone lines, automatic switches. means controlled from a calling one of said lines for operating a series of said switches to extend a connection to 21 called one of said lines, a finder switch, means controlled from the Said called line for initiating the operation-0f said tinder switch, and means controlled from the called linefor then extending said connection to include another called one of said lines.

53. In a telephone system, telephone lines, automatic switches, means controlled from :1 calling one of said lines for operating a series of said switches to extend a connection to a-called one of. said lines, a finder switch associated with the last switch of said series, moans controlled from the called line for initiating the operation of said tinder switrh to extend a connection to one of said automatic switches, and means for then extending said connection to another called one of said lines.

54. In :1 telephone systemfa telephone line. a non-numerical switch individual to said line, an operating magnet for said switch. a switching relay therefor, a circuit for said magnet, mean for energizing said switching relay to open said circuit, and ad- (litional means for operating said magnet while said switching relay is maintained energized.

55. in a telephone system, a calling line, a trunk line terminating in an automatic switch, called'lines accessible to the said switch, relays for rontrolling the operation of said switch, means for connecting said line with said trunk line, means controlled from said calling line for operating said rclays to cause said switch to connect with one of said called lines, means controlled from thccnllcd line for releasing said switch, and other relays in the switch controlled from the said called line for causing said switch to connect with'anii ther of said called lines.

56. In a telephone system, telephone lines, automatic switches, means controlled from a calling one ot said lines for operating a series of said switches to extend a conneclion to it called one of said lines, a switch individual to the called line, a circuit for operating said individual switch which includes a wiper of the last switch of said scrics, and means controlled by the subscriber on said called linefor closing aid circuit.

57. In a telephone system, a calling line, a calling device on the said line, automatic switclngis, called lines, means controlled by the calling device-on the said culling line for operafiin a series of said switches to extend a connection to one of said called lines, I

moans controlled from the said called line for releasing part of said series of switches while maintaining a connection with the calling. line, means controlled by the calling device in the calling line for then extending a connection to a second one of said called lines, and means for preventing the calling impulses from being heard by the-subscriber on the first called line during the establishment of the second connection.

58. In a telephone system, a series of selectorswitchcs, a. final connector switch accessible to the last of said selectors, means for operating said switches over a calling line to set up connection with 0. called line, means for producing interruptions in the called line, means responsive to one of said interruptions for releasing said connector switch and preventing the release of said :rlcctors, and means for reoperating said connector over the calling line to Set up R new connection.

ulii. 21%

limneh iBXCiMIaL lmzll (filiflfi 'l in the hraneh e "hair for use in (on wt ng local 000mm ions, humming selenium for l; i-ompleting l'liilli ljrilnill emlw nortions. L1 lines lr'en i: exclnmg'ihr-h iermii coming conneeto' V switches for the hrzmcih nu'i! have divert our): 1* to -l of Bl. In :1 telephone v mlleil line, a prP-grewiwzrly MP7? for connecting will linoa, in Ming Htllll switch two line r All over said calling and c:

il'iii h; I), each relay rnntrolling ll-iu nmgnut to operate the hwn'z'h to amend I'UllllLKIlHlL (32. In :1 wiegfhomj :a e'tem an swituh having :2 line relay ('Qllll' l calling line to operate 551ml with n cullml ine, a EHUlltl switch for we; llim: e 2L liiiklk llivlll lt i12- f line. anal mi on the culled l line relzw {i to imnel'ztle (323. In e. snih'il having milling line to l 4 with :1 called line, a fllkf jllti lit 5 ill switch for c .-ntrolling the erd tion Hint-0 a hack hriilge rein energized m" ill;- rni t'Ll line. {lIl'Il mouna ml in l ill iho uliwl Sill wa l? her i :1 of .nml v n: i l:: izalrq illii llm ill: winl 5W (mil line re in plum; oi relax; in orrler U- muhie ll scrilwr to reopeinte 5n (ll. 1212i telihlmiu P mu -r.

2: iii:

in each con tinder s im-hoe it: mun m 'lh o i r,

moi- 21mm ie ml w lling in Sillll line and terminals for from said line, an uutomutie ill la "7. line for moving the lust ment niwnns for operating said line switch as my: to liml the eonneetn'in extended 5 'eto from another calling subscriber and 'or ogwmting the line switch to automatievt it trunk when the call is extended united line. t,,l!)llt)ll'l n tem, a line. trunk ti 5120i into groups, a pair of wiper: runne i h mill line and lnlliYilllllll and mean, for operating mid wiper, all i- (mule-ll to the line to non \i'hh 5 ii 1m in one group or for ope/rut Winn It will is xlenilml from n only with a trunk in he other group to wumplele the vonnertion f'eiegj-ln-mstem a line, a line inun'iilnzl thereto. a plurality of trawl; linw: ziwwsril l thereto, part. of aid trunk lines for i only in Calls from said line :r'ml wh n j ror um only in calls to said lino, menns for on Hing sa d ltl.'l1 to selr-vt only an idle outgoing trunk when the mm the line and means for operatleet only one of the 111- When '11 (all 13% extended to in ielephmie systenn calling and ii snhser we, means under the control of a. walling ennsvriher for establishing a minim-li n with a milled llllF killlfll' through w of zlulomliiiv f-"fl'llfl'llc lllt'il \\'lh'r' tho alled FEl M'E llIlL may (ll$'l\lll' 1.3min all the will vunmwlinn by rrllnr-im; l s" ill\ll!llllllll "filll'lilfi Illlll "i the vnlll!" i'llir Fun will main to i emmeetion and re' trialled means for mining one of Flliti t ing a call from the main mm- 2 it) one :12 wntroiied aver the sailing line for then exsnitl lines by means (if one of .w ii mmunnq t'onutttorb', 111 321115 .irutiuihng Elm iinc :3 uf the allied line for enabling iii: (Iiliifiti sui Stfiiilill' It) reo x-rutin the inrouiiug (mu tor in use to mimic-i the t'ail and humus 't'm' enabling! thv mil-2d suhi ciiihz r to ii'zilfiivi' thv cal! to nnuthcr hut: in case the: line in wh't-h it was that attempted to transfer it; hug

73. In a telephone system, toluphonn iinw, ztuloniatic swittiltls irontruiied from ti culling one of said line: for LXitlltiil'lgg; a cenmmtimi to a culled one of Stliti iinrs. n5 mntrniiutl from the culled iin um of mi" :iution'uitin switvhr ,lFiti for wprmtiug, it to extuiui the ttililftt 1 am it) i: a't-t'tuni ailiit Uni of s-uftl hues, and 1m aim again l'li/ ing and rcopui-aiing mid awuvh in min-n; the connection 1:) it third Qliittl hiuin \TJPJ ti? SPL'OIXL'I tailed inn: is husy.

T4. In a ttlephunt: mun tvi shtmv hue; automatic switr-hm 'i'tnliiiiitti ruin it milling 0116 of Haiti iintrx 2hr chit'huingl 1 cunuwtinn to a called one ()i mid ilnw. nit-nus t-nntruiir-ti from the catihui iin fur rnh'nsing U110 uf HI iIi automatic swi chua and for thou rmgierntiug it tn tXiPnLi (he mum-Minn to a; swmui ii-nihiti 0110 (if Said 11957 and int-um im' vnuhling tin: first unihwi EUifiatjl'iiiffi it; again rub m mid automatic switch at any tiuutzit the respmzz-v of the H'LOiid (:tziiwi suhsri when calling. a COIH'IHIUM siiiti-h and H'lt'fitl'li for operating it in vxit'uii :1 POM}! V um tn mm (if ztiti ilntr us :i (21 iieti iin jz, SitiNC'i'lilH tron- I wrihers iillt' a mniiccior switch t-ontrolied m'ur said lim to extsnd a rounerli'in to :1 ('tlihhi iinv, IXIZHJ5 controilvd over the stud :xniitd 'line fur rt-imsing said switch, means (nu-trolled HYPE either thv mailing or called iimfur thvn rcnpi ratiug said switrh to ttmwi'ur tiw mti in another (hilt-(i line, and is; aim. for pi'mnuting tii ittlitillivP in 2110 rvwiwr hf liit' iim mt tmmi'vrring the 62K ]l'.t--[)t3\ti'\t' u! uhi h iinv timthe traininwih-u hiutin-ext uding11w trunnoctimi to a hli wnii-zii party by rmpurut'ingg one of mid Wiitfiitw usual in said first vstnhlishv'l t'trllllt iifill.

T in a ikifllilfiiid s 'bttnn, subscribers iinw H1(LH\ inr'httlingg :1 iscries of automatic :-'\\'it =h -a-- fir wtsihlis-hing a talking: circuit {ruin n vniiir; in n cniimi one of said lines, EHP'EXI" uuntruiimi h the fliitti suhsrriber for rt-v it; 0m of the switvhes in the series illili int nminhtiuing said switch under his runtrui.

NY. in n tvlophunc s stcn'i, subscribers iinrs. means including :1 M'Iitfi m uutflmatic Fufhzht int t'. i:'li)ii:5i1ih if n talking: circuit f -win a milling! tn :1 (t iiwi one of Said lines, muiua LUHilUiiti it the (Jailed suhwrihor for r ism' .JHC Oi thv itvhrs; in the st-lit and i'm' nnzmtnining ni'i switvh unilm his runtwi nsati .iui mritch vontmlimi hy the t'ttlimi St'i'ii l'i' t0 vxtmiti i-l hrzinth of Htiti tulh'in t-m-uit -5) n FtW'l'Hili 4 411011 anhuvrihur.

lied hy m0 at Chiwngm (moi-c County IiiiHUJQ, ihis Nth tin of Ocmim1l917.

RGDNEY G. RHHARDSON. 

